In the previous study, we have obtained the spontaneous emission spectra for a quantum well embedded in planar
microcavity laser by the numerical integration. Although the numerical integration in the spherical coordinate can given
the spontaneous emission for the QW in any microcavity lasers, one would be like to obtain the analytic expression. A
new analytic expression for the TM mode spontaneous emission spectra in the planar microcavity laser typically
consisting of half a wavelength λ<sub>ο</sub> is given in this paper. The results show that TM mode spontaneous emission spectrum
by the new analytic expression agrees well with that in the numerical integral in planar semiconductor microcavity laser.
The main part to control the TM mode spontaneous emission spectrum is found in the analytic expression. The new
analytic expression can be used to study the TM mode spontaneous emission spectra with a quantum well in the
Hydrogenated amorphous silicon thin film solar cells are prepared using radio frequency plasma enhanced chemical
vapor deposition on polyimide substrates. The structure of the cell is polyimide /Al/n-μc-Si:H/i-a-Si:H/p-a-SiC:H/TCO.
Due to amorphous silicon cells have Staebler-Wronski effect and their efficiencies do not stabilize at prepared, so these
cells were placed more than fifteen months and I-V characteristics of these cells were measured in four times. They
include (i)in the initial, (ii) placed in desiccator over fifteen months, (iii) light-soaked for five hours under AM 1.5
(100mW/cm<sup>2</sup>) and (iv) annealed for two hours in natural conditions. The measurement results such as open-circuit
voltage, short-circuit current, resistance in series, parallel resistance, conversion efficiency and fill factor are given and
studied. Staebler-Wronski Effect are found and explained with these parameters. Generally, after light-soaking, the
short-circuit currents of cells increase, the fill factors and open-circuit voltage decrease and the reduction of the
efficiency is proportional to the fill factor. Abnormal Staebler-Wronski Effect appears in a cell. The cause of these
phenomena is analyzed. The consequence that the efficiency varieties with the fill factor is derived r. A graded gap in P-I
interface can be improved the cell efficiently. Ultimately, the stability of a-SiH thin film solar cells on polyimide
substrate is discussed.